Spot welding apparatus



Dec. 7, 1948.

w. H. DAILEY, JR

SPOT WELDING APPARATUS Filed May 26, 1948 3 Sheets-Sheet 1 Dec. 7, 1948.

w. H. DAILEY; JR

. SPOT WELDING APPARATUS Filed May 26, 1948 3 Sheets-Sheet 3 minumberof spot -welds.

Patented Dec. 7, 1948 men ismres :PAT ENT SPOT 'WELDING APPARATUS 'William; i Dailey, .Jr., Library; "Pa assignor .to

l. Carnegierlllinois .Steel Oorporatiom;ancorpora- Applicationi'May' 26, 1948; Serial No; 29 337 c8lClaims.

I 1 This invention relates to apparatus for spot .swelding metal strips, -particularly for joining wstrlps preliminary 'totheir entry to a continuous processing iine;--suchas a box annealing furnace.

" when metal strips-are treated in continuous v eproeessing lines; the trailing end of each strip is-we'lded to the-leading-end -of the strip following. -For most purposes-the-strips are lap welded; that lsythexstrip ends are-overlapped and joined by a ewelded,' 'they =must be accurately-aligned longitu "dinally,'-'and:preferablythe welds are placed in straight dines perpendicular to the longitudinal :center' line-of' the=-strips to distribute pulling stresses-umformly acrossthe width. 'To afford.

time for-weldingthestripends i without stopping eontinuous-lines, such lines commonly have a -looper pit, which is beyond the Welding station eand in whi'ch a considerablelength of slack strip accumulates. The lag aiiorded by the looper pit-- -is-rather-brief g hence the strips must be aligned and-melded expeditiously.

iAn Object-Ofithe presentinvention is to provide improvedspohweldingapparatus which aligns the i-strips-expeditiouslyt and accurately and weldsethemiiand controlsxthe position of the welds.

;rA::turther=-nbject;.-of theinvention is V to provide iscsimpleiand rugged; spot. welding apparatus that zpositinns:the.ends:;ofi:.strips accurately in align- .cment,r: clamps uthe ends together. and applies istnngs iofsispoti welds" in: straight lines across the (strip; perpendicmaruto the. longitudinal center line.

rinaccomplishingithese and other, obiects of the zinvention;I havey--provided improved details of ratsticture; alpreferred form of which is shown in ntheiaccompanymgf drawings; in which:

,r ii'lzure 1;is a top plan'view of an improved weld- ;ingigapparatus 'embodying'features of the present :ainvention;

:Figure. 211s a vertical sectional view of the lepparatus. takenrsubstantially on line 11-11 of lf s el;

fFigure 3 is,- afrontelevational view of the apperatus,;.-partlyin section;

=-Figure 4 is a verticalsectional view taken sub- Manually .oniline. IV-IV, ,0: Figure 2; and

rEigurel 5 is awerticalsectional view taken sub- .stantiallylon line V-i-V ofFigure 3.

iiReierringtmore inidetail to the drawings: lIhe-weldingapparatus of the present invention comprisesa" sl pport I 0, which has a flat horizontal liable 1tpp=:l2--a-long; which strips S and S pass lweliminary to their; entry :to; a, continuousprocright to left as viewed-in Figures 1 and 2. 'i'T'he side of the support atlthe left as viewedinFism'e 3 is the position of 'anroperator'offltheapparatus. The table top has a facing-130i electricallyconductivematerial which furnishes-one electrodeior conducting welding I current :to -the i strips. *1 The underf ace of "the-table .top has a i longitudinally extending guide rail 14: spaced fromnoneuof: its edgesiFigur-es 2"and 4).

Longitudinally extending: stripwg-uideabars 1 and: i! are carriedvon the table topaonitheside away" from the operators position .andaareaadjustable transverselyof.thetable top i Eigures 1 and 5). Preparatory to wel'ding, stripsxs iand'is are aligned longitudinally-against these'guide bars and their ends are overlapped. 'jThe adjusting means for. the. guide bars convenientlyxincludes a pair of spin'dles'bl81 and l9' f0reachaguide zbar. Said. spindles are .accessiblef-fori adjustment at the operatorsposition and.v are rotatablyreceived in bearings 2ilifixed tothe.underside-ofjtheztable top, and; threadedly engaged withfibearingszzl, which. arefixedzto-l'the guide barsrand; extend through transverse slots .22 in theetable; top.""?lfI:he spindles of each "pair; are; connEctedzttovrotate together i by a chain and sprocketasmechanism '23.

A transverse frame zlzibridgesztheitablewand :is formed of side plates 25.and:26.,\a:transverseibeam 21, which connects the-sideplateswmidwayz ofitheir height, and. a transverse .trackwayrn;iwhichsconnects the side: plates attheirtupper textremities (Figures 2 and 3). i Rol1 ers:i29a are rotatablycarried on the side platesiand'rest on theatablezztop, thus supporting:v the rframe :on the table. topefor adjustment.v longitudinallyx'of': the: flatter. 'L' Rreferably side .p1ate325. at theoperatorsiside ofxathe support carries: a handle to. facilitate, adjustment of the frame withrespecttto thetable.

The bottom edge of:- side ;plate 26': hasten :elongated inwardly nextendingwflange; 3 I z.;(=F.iguresii i1, 2 and 4). lnnenrollers :32iand outeramllerssfl are rotatably; carried =on:i:;flange :3 l :tandyengage the inside andoutsidetfaces .respectivelytof-iguide rail 14; thus constraining.movementtof the -f-rame to a straight longitudinalpathJ-J Lock barsehand 35 are -fixedtoside;v plates :25 and-e126 :directlyl-ibeneath the edges fofzt the-:rtableiutopp buttnorm'ally clear the latter sufiicientlyltoapermit" freellongitudinal adjustment inf the-:1frame; *-Whenithe frame is liftedin a'mannerahereina'fter explained, SfiidflOCk bars: engageithe=undenfacewoffithe table top and-fix 'the-frame with respect to thezsupport.

. Transverselbeam zlthasldownwardly extending xhinge brackets 36 (Figures? 2:and:1.3). eAfl clamplusi nmline. l 'I'he,,;direction of strimtravelis from {'55 ingpplatez 31 is: hmged'atdtsreanto -said brackets and has a substantially flat forward portion 38. The clamping plate has a lowered position, in which its flat forward portion 38 engages and holds overlapped strips S and S on the table top, and a raised position in which it clears the strips. Beam 21 carries a double acting pneumatic cylinder and piston 39. A piston rod 40 operatively connects the piston to clamping plate 31 for raising and lowering the latter, the joint between the rod and plate being sufficiently loose that vertical movement of the rod can swing the plate about its hinge to the extent necessary. Any suitable valve mechanism may be employed for controlling admission of fluid to the cylinder, a hand operated valve 4| carried on side plate 25 being illustrated. Lowering the clamping plate simultaneously lifts the frame and thereby moves lock bars 34 and 35 into engagement with the under face of the table top. Thus operation of a single control both fixes the frame with respect to the table top and clamps the overlapped strip ends firmly together, the strips previously having been aligned against guide bars [6 and I1.

Trackway 28 preferably comprises a pair of spaced apart upper rails 42 and 43 and a pair of spaced apart lower rails 44 and 45 arranged as .best shown in Figure 2. A welding carriage 46 is supported on the forward side of frame 24 for transverse movement across the support. Said carriage includes a vertical plate 41 which rotat ably carries a pair of axles 48. Rollers 49 on said axles ride between the upper and lower rails of the trackway. Preferably the axles are reinforced by a brace 50. Preferably the lower edge of plate 41 rides against the top of beam 27, being retained thereon by a guide strip welded to said beam. Preferably plate 41 carries a handle 52 extending to the operators side of the apparatus (Figure 3').

The face of plate 4'! carries a pneumatic cy1inder and piston 53 which has a downwardly extending piston rod 54. The piston rod is movable vertically and preferably it extends through a guide bushing 55 fixed to the face of plate 4'! beneath the cylinder. The lower end of piston rod 54 carries one or more electric welding guns 55 of a known construction. Electric current is conducted to said guns via cables 5'! and cooling water is circulated via hoses 58.

The piston and cylinder effect raising and lowering of the welding guns. When the guns are lowered they engage the strips and apply spot welds thereto. Admission of air to the cylinder is controlled by any suitable valve mechanism, preferably being foot operated in order that the "operators hands may be free for positioning the carriage and frame and operating valve 4|.

The structure of the various valves, pneumatic cylinders and pistons and welding guns has not been illustrated in detail for the reason that these are standard parts and their structure per se is not part of the present invention.

In operation, a strip S passes along table top H on its way to a continuous processing line. When the trailing end of strip S reaches the table top, the leading end of a new strip S is introduced to the table top and the two strips are long tudinally aligned against guide bars l6 and H and their ends are overlapped. Frame 24 is adjusted longitudinally of the support to a position in which welding guns 56 are directly over the line at which it is desired to apply a String of spot welds. Valve 4| is actuated to lower clamping plate 31 into engagement with the overlapped strip ends and simultaneously to raise the frame and. fix its position with respect to the support.

The welding carriage 46 is moved across tracl way 23 and at frequent intervals, the foot valve is actuated to apply spot welds. The welding circuit is completed whenever the welding guns contact the strips, since the latter are always in contact with the other electrode, the electrically conductive facing l3 on the table top. Additional strings of welds may be applied to the strips by releasing frame 24 and changing its position.

From the foregoing description it is seen I have provided a welding apparatus of simplified construction and operation and which expeditiously aligns the strips and applies welds in straight lines perpendicular to the longitudinal center lines of the strips.

While I have shown and described only a single embodiment of the invention, it is apparent that modifications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

l. A welding apparatus for joining ends of metal strips comprising a support having a flat surface along which the strips may pass, a transverse frame bridging said support and'being mounted thereon for longitudinal adjustment, a clamping device carried by said frame and having a lowered position in which it is adapted to engage and hold strips on said support and a raised position in which it clears the strips, motive means on said frame operatively connected with said clamping device for moving the latter, and a welding carriage carried by said frame for transverse adjustment and having a vertically movable Welding device engageable with strips on said support.

A welding apparatus for joining ends of metal strips comprising a support having a flat surface along which the strips may pass, av transverse frame bridging said support and being mounted thereon for longitudinal adjustment, lock means on said frame for fixing said frame with respect to said support, a clamping device carried by said frame and having a lowered postion in which it is adapted to engage and hold strips on said support and a raised position in which it clears the strips, motive means on. said frame operatively connected with said clamping device for moving the latter and simultaneously operating said lock means for fixing or releasing said frame with respect to said support, and a welding carriage carried by said frame for transverse adjustment and having a vertically movable welding device engageable with strips on said support.

3. A welding apparatus for joining ends of metal strips comprising a support having a fiat table top along which the strips may pass, an electrically conductive facing on said table top, a transverse frame bridging said support and being mounted thereon for longitudinal adjustment, lock means on said frame for fixing said frame with respect to said support, a clamping device carried by said frame having a lowered position in which it is adapted to engage and hold strips on said table top and a raised position in which it clears the strips, motive means on said frame operatively connected with said clamping device for moving the latter and simultaneously operating said lock means for fixing or releasing said frame with respect to said support, and a Welding carriage carried by said frame for transverse adjustment and having a vertically movable electric welding gun ensageable with strips on said table topff 4. A welding apparatus for joining ends of metal strips comprising a support having a fiat'table top along which strips may pass, an'electrically conductive facing on said table top, guide means on said table top for aligning strips longitudinally preparatory to welding, a transverse frame bridging said support and being adjustable longitudinally of the support, a clamping plate hinged to said frame and having a, lowered position in which it is adapted to engage and hold strips on said table top and a raised position in which it clears the strips, motive means on said frame operatively connected with said clamping plate for moving the latter, and a welding carriage carried by said frame for transverse adjustment and having a vertically movable electric welding gun engageable with strips on said table top.

5. A welding apparatus for joining ends of metal strips comprising a support having a flat table top along which strips may pass, an electrically conductive facing on said table top, guide means on said table top for aligning strips longitudinally preparatory to welding, a transverse frame bridging said support and being mounted thereon for longitudinal adjustment, lock means on said frame for fixing said frame with respect to said support, a clamping device carried by said frame and having a lowered position in which it is adapted to engage and hold strips on said table top and a raised position in which it clears the strips, motive means on said frame operatively connected with said clamping device for moving the latter and simultaneously operating said lock means for fixing or releasing said frame with respect to said support, and a welding carriage carried by said frame for transverse adjustment and having a vertically movable electric welding gun engageable with strips on said table top.

6. A welding apparatus for joining ends of metal strips comprising a support having a flat table top along which strips may pass, an electrically conductive facing on said table top, guide means on said table top for aligning strips longitudinally preparatory to welding, a, transverse frame bridging said support and having side plates, a transverse beam and a transverse trackway connecting said side plates, rollers on said side plates mounting said frame on said support for adjustment longitudinally of said support, guide means on said table top and said frame constraining the adjustment path of said frame, lock means on said side plates for fixing said frame with respect to said support, a clamping plate hinged to said beam and having a lowered position in which it is adapted to engage and hold strips on said table top and a raised position in which it clears the strips, motive means carried by said beam and operatively connected with said clamping plate for moving the latter and simultaneously operating said lock means for fixing or releasing said frame with respect to said support, and a welding carriage carried by said trackway for transverse adjustment and having a vertically movable electric welding gun engageable with strips on said table top.

7. A welding apparatus for joining ends of metal strips comprising a support having a flat table top along which strips may pass, an electrically conductive facing on said table top, guide means on said table top for aligning strips longitudinally preparatory to welding, a longitudinal guide rail on the underface of said table top, a transverse frame bridging said support and having side plates, a transverse beam and a transverse trackway connecting said side plates, rollers on said side plates resting on said table top and mounting said frame for adjustment longitudinally of said support, additional rollers on said side plates engaging opposite faces of said guide rail and constraining the adjustment path of said frame, lock means on said side plates for fixing said frame with respect to said support, a clamping plate hinged to said beam and having a lowered position in which it is adapted to engage and hold strips on said table top and a raised position in which it clears the strips, fluid pressure means carried by said beam and operatively connected with said clamping plate for moving the latter and simultaneously operating said lock means for fixing or releasing said frame with respect to said support, and a welding carriage carrled by said trackway for transverse adjustment and having a vertically movable electric welding gun engageable with strips on said table top.

8. A welding apparatus for joining ends of metal strips comprising a support having a flat table top along which strips may pass, an elec-- trically conductive facing on said table top, transversely adjustable side guides on said table top for aligning strips longitudinally preparatory to welding, a longitudinal guide rail on the underface of said table top spaced, from one edge, a transverse frame bridging said support and having vertical side plates, a transverse beam and a transverse trackway connecting said side plates, rollers on said side plates resting on said table top and mounting said frame for adjustment longitudinally of said support, additional rollers on one side plate engaging opposite faces of said guide rail and constraining the adjustment path of said frame, lock bars on said side plates engageable with the underface of said table top for fixing said frame with respect to said support, a clamping plate hinged to said beam and having a lowered position in which it is adapted to engage and hold strips on said table top and a raised position in which it clears the strips, double acting fluid cylinder and piston carried by said beam and operatively connected with said clamping plate for moving the latter and simultaneously engaging or disengaging said lock bars with the underface of said table top, and a welding carriage carried by said trackway for transverse adjustment, and having a vertically movable electric welding gun engageable with strips on said table top.

WILLIAM H. DAILEY, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,362,388 MacChesney et al. Nov. 7, 1944 2,369,830 Johnson et al Feb. 20, 1945 

